Airtac SEJ Adjustable Cylinder SEJ50BX75-40S
The AirTAC SEJ Adjustable Cylinder SEJ50BX75-40S is a genuine double-acting ISO 15552 double-rod cylinder with a mechanically ADJUSTABLE stroke: a back-rod stop screw lets you fine-tune the retract end over a 40mm window, so this Ø50mm unit covers an effective stroke of 35–75mm without changing cylinders. Force is equal in both directions.
- BoreØ50 mm
- Nominal stroke75 mm
- Adjust window40 mm
- Effective stroke35–75 mm
- Port sizePT1/4
- CushionAdjustable, 30 mm
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac SEJ Adjustable Cylinder SEJ50BX75-40S
The AirTAC SEJ50BX75-40S is a double-acting, double-rod ISO 15552 profile cylinder featuring a 40 mm adjustable stroke window. A rod exits both ends, meaning the annular area is identical in both directions and yields an equal force of 825 N each way at 0.5 MPa. By turning the stop screw on the back rod, you can mechanically dial the retract end position to anywhere within an effective stroke range of 35-75 mm without swapping hardware.
Configured with a SUS304 stainless steel rod (code B), this cylinder is built for corrosion resistance and washdown environments. It includes a magnet (code S) for position sensing with CMSE reed or DMSE electronic sensors. The extruded aluminum barrel contains no external tie rods, and field-adjustable air cushions at both ends decelerate the load near the stroke extremes without acting as a mechanical lock.
Airtac SEJ Adjustable Cylinder SEJ50BX75-40S Technical Specifications
| Model | Airtac SEJ Adjustable Cylinder SEJ50BX75-40S |
|---|---|
| Series | SEJ ISO 15552 adjustable-stroke cylinder |
| Bore size | Ø50 mm |
| Nominal stroke | 75 mm |
| Adjustment window | 40 mm (35–75 mm) |
| Configuration | Double rod, double acting |
| Port size | PT1/4 |
| Rod thread | M16×1.5 |
|---|---|
| Operating pressure | 0.15 – 1.0 MPa |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C (0–150 °C with FKM seals) |
| Speed range | 30 – 800 mm/s |
| Cushion | Adjustable, 30 mm |
Specifications follow the official AirTAC SEJ datasheet and ISO 15552 / VDMA 24562 dimensions. The adjustment screw shortens the retract end only; do not exceed the 40mm window. Port options: PT (standard) / G (BSPP).
Theoretical Output Force (Ø50mm)
| Pressure | Force (both directions) |
|---|---|
| 0.5 MPa | 825 N |
| 0.7 MPa | 1155 N |
| Max (@1.0 MPa) | 168 kgf |
A rod exits both ends, so extend and retract force are identical. Actual usable force is lower than theoretical; size with a safety margin.
Model Code: Airtac SEJ Adjustable Cylinder SEJ50BX75-40S
| SEJ | ISO 15552 double-rod double-acting cylinder with adjustable stroke. |
|---|---|
| 50 | Bore size in mm. |
| ×75 | Nominal stroke length in mm. |
| -40 | Adjustment stroke window in mm (options: 10/20/30/40/50/75/100). |
| -S | Optional built-in magnet for CMSE / DMSE sensor sensing. |
Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B). Seals: TPU (blank) / FKM high-temp (H) / NBR (N). Thread: PT (blank) / G. Mounting (SEJ): Basic, LB, FA, TC, FTC, TCM1, TCM2. Related: SED (double rod, fixed stroke), SE (single rod).
Where the Airtac SEJ Adjustable Cylinder SEJ50BX75-40S Is Used
Packaging Stop Calibration
Dial in the 35-75 mm retract stop to precisely strike a sealing jaw on a packaging machine, using the equal 825 N both-way force to consistently crimp carton flaps.
Bottling Line Changeover
Adjust the back-rod stop screw to accommodate different bottle heights on a conveyor, relying on the SUS304 rod for corrosion resistance during daily washdowns.
Press Fit Commissioning
Fine-tune the end position during a CNC lathe door trial, locking the stop screw after finding the exact engagement point for a robotic loader.
Is the Airtac SEJ Adjustable Cylinder SEJ50BX75-40S the Right Cylinder?
Verify the 40 mm adjustment window covers your required end-position range; if you need less fine-tuning, a fixed-stroke SED double-rod cylinder may suffice. For sizing both ways: stepping down to a 40 mm bore yields 528 N both ways at 0.5 MPa, while stepping up to a 63 mm bore provides 1402 N. This 50 mm bore delivers 825 N at 0.5 MPa and 1154 N at 0.7 MPa. A plain SEJ does not hold position on air loss; for fail-safe holding, specify a BSED or an external rod lock. Ensure your ISO 15552 replacement matches the 75 mm stroke, 40 mm window, PT1/4 port, and mounting choice from Basic, FA, LB, TC, FTC, TCM1, or TCM2.
Quick checklist
- ✓ Need on-machine stroke fine-tuning?
- ✓ Adjustment window (40mm) covers your range
- ✓ Equal force both directions OK
- ✓ Port/thread type (PT/G)
- ✓ Magnet (-S) for CMSE/DMSE sensors?
Installation & Maintenance Notes
- check Use clean air filtered to 40µm or finer.
- check Keep within 0.15 – 1.0 MPa operating pressure.
- check Set the stop screw within the 40mm window; lock it after adjusting.
- check Adjust end cushion screws for smooth stops.
- check Use correct mounting accessory (LB/FA/TC/FTC/TCM1/TCM2).
- check Installation by qualified personnel per AirTAC docs.
Airtac SEJ Adjustable Cylinder SEJ50BX75-40S FAQ
A stop screw on the rear rod lets you mechanically shorten the retract stroke over a 40 mm window. The effective stroke range is 35-75 mm. You dial the end position during machine commissioning and lock the screw in place.
Because it is a double-rod cylinder, the force is equal in both directions. It delivers 825 N at 0.5 MPa, 1154 N at 0.7 MPa, and a maximum of 168 kgf at 1.0 MPa.
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